Which Vitamin D in CKD-MBD? The Time of Burning Questions

Table 1

Vitamin D sterols currently available as medical treatments in nephrology field.

	Nutritional vitamin D		VDRA
		Hydroxylation required to activate VDR		Hydroxylation required to activate VDR
Vitamin D2; and its analogs	Ergocalciferol	25-hydroxylation and 1-hydroxylation	Paricalcitol; 19-nor1,25(OH)2D3	—
			Doxercalciferol 1a(OH)D2	25-hydroxylation
Vitamin D3; and its analogs			Calcitriol; 1,25(OH)2D3	—
	Cholecalciferol	25-hydroxylation and 1-hydroxylation	Alfacalcidol 1a(OH)D3	25-hydroxylation
	Calcifediol	1-hydroxylation	Oxacalcitriol 22oxa1,25(OH)2D2	—

Note: all the VDRA reported in the table are considered analogs with the only exception of calcitriol, which corresponds to the natural form of 1,25(OH)₂D₃.
LVDRA: vitamin D receptor activators; VDR: vitamin D receptor.